More diffractive opticsCanon seems to still invest significant money into developing their diffractive optics technology. Currently Canon has 2 DO lenses, the very good 400 f/4 DO IS and the decent 70-300 DO IS.

EF 600mm f/5.6 DO

Making long lenses that are smaller and lighter will always be desired, especially with the boom in digital cinema cameras and wildlife photography.

More patents have appeared, one for a 600 f/5.6 DO and another for an 800 f/5.6 DO. The 800 would measure a miniscule 46cm in length.

EF 800mm f/5.6 DO

Chances of coming to market? I think it’s a pretty solid bet we’re going to see new DO lenses announced sometime. When? Your guess is as good as mine.

With Canon Rumors suggesting the (rumoured) 100-400 4-5.6 will replace both the old zoom and the 400mm 5.6 prime, what are the chances of a 400 5.6 DO lens, priced below £1500, and aimed at the enthusiast wildlife/sports 'tog. Could have and L designation or not, i dont care as long as its good.

I doubt youll see a 400 5.6 DO soon as the weight of the current 100-400 is not very great itself, and I very much doubt it would be $1500 seems far too low. The DO is all about portability and is more beneficial as conventional lenses get heavier, the reason why we are seeing patents for the big primes at the moment. As its new technology, its expensive and people arn't going to pay a premium for a 30% weight saving on a lens that is already easily manageable/portable. As time goes on then you may a see a shift with more DO lenses and may even replace conventional lenses if the optical quality is the same, but I feel this is a long way off at the moment. The 400 f4 Do has been relatively successful as it fills a specific niche for those people who dont want the weight of the 500+ but need the reach + TC usage and f4.

Personally, I'm holding out for the TS-E 12-1200 f/0.95 L IS pancake....

b&

or the 8-1500 f1.2L H-IS macro with 1.4/2x built in extender

But only if you can use both extenders at the same time without a drop of resolution or contrast on the 80 MPixel APS-C 7D M2. Also everything below 90 degrees of tilt or below 50mm shift is just so lame.